Crane



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MOVABLE on COLUMN Dec. 27, 1966 P. H. PERSON I 3,294,262

CRANE Filed Nov. 9, 1964 Pam? H. PERSON ATTORNEY United States Patent f 3,294,262 CRANE Philip H. Person, Moon Lake, Mich., assignor to Lake Shore, Inc., Iron Mountain, Mich., a corporation of Michigan Filed Nov. 9, 1964, Ser. No. 409,667 3 Claims. (Cl. 21458) This invention relates to a crane which can be attached to -a fork truck to provide a highly useful mobile crane unit.

The principal object of this invention is to provide a simple, versatile crane attachment for fork trucks.

Another object is to provide a crane construction permitting simple mounting on and removal from a fork truck.

These objects are realized in the illustrated construction in which a simple boom can be attached to a fork truck by running the forks into stirrups carried on the ends of the compression members of the boom and attaching the tension member of the boom of the fork truck. The crane can be raised and lowered by the usual expedient used to raise and lower the fork. The tension member is preferably adjustable and this factor coupled with the ability to raise and lower the crane results in mounting the hoist drum on the compression members so changes in position of the hook (load) relative to the boom are not compounded on movement of the boom as would be the case if the hoist drum was on the truck. The hoist is preferably hydraulically driven with the hydraulic source being the source on the truck. The problem of removing the crane from the truck has been solved by providing a hook on the end of the boom to allow the hook to be engaged on a suitable hook, etc. on a wall, post or the like so the fork may be backed away from the crane while the crane is so restrained. The crane can then be stored with the end so hooked and is ready for mounting at any time.

Other object-s and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings, in which:

FIG. 1 is a side elevation of the crane mounted on a fork truck and shows the hook on the wall for removal and storage;

FIG. 2 is a fragmentary view taken as indicated by line 22 in FIG. 1;

FIG. 3 is a fragmentary View from line 3-3 in FIG. 1 (it should be noted that neither FIGS. 2 nor 3 attempts to show great detail of the fork truck mechanism); and

FIG. 4 is a view taken on line 44 of FIG. 1.

The fork truck in the drawings is shown for illustrative purposes and the various types of construction of fork trucks currently employed can be used with this type of crane. Here the vehicle is provided with a relatively fixed forward column 12 which is pivotally mounted on the vehicle at 14 so that the angle of the column with respect to the vehicle can be varied by adjusting the hydraulic ram 16. Movable column 18 is slidably mounted on the fixed column 12 and is actuated by means of a hydraulic ram, not shown. The movable column is also provided with a chain or cable arrangement which, in turn, connects to the fork assembly including the forwardly projecting forks 20 and the back portion 22. Therefore, as the sliding column 18 is elevated by the hydraulic ram the fork assembly is elevated both with respect to the sliding column 18 and the fixed column 12. The details of this type of construction form no part of the present invention.

Crane assembly or boom 24 which includes compression members 26, 26 pivotally connected to the tension member 28 at the free end of the boom can be mounted 3 ,294,262 Patented Dec. 27, 1966 on the fork truck through the provision of the articulated stirrups 30 carried at the lower ends of each of the two compression members 26 while the tension member is provided with a suitable boss 32 permitting the tension member to be pinned to the upstanding ears 34, 34 provided on the back 22 of the fork assembly. The stirrups 30 are designed to slide over the forks and seat against or such. It will be noted the two compression members 26, 26 will hold the stirrups in place without pins or such. It will be noted tht two compression members preferably terminate at the cross tube 36 through which a long bolt is passed to permit pivotal action of the compression members with respect to the stirrup and the fork truck. The tension member is provided with a hydraulic ram assembly 38 with suitable hoses 40, 42 running back to the fork truck and controllable therefrom, as for example, by means of one of the control levers situated next to the drivers seat. This permits adjusting the length of the tension member and, therefore, adjusting the angle of the boom with respect to the fork truck. It will be appreciated that this feature could be omitted and some degree of adjustment could be obtained by providing an adjustable pin and telescoping tube arrangement on the tension member or in some cases a fixed length boom will be quite satisfactory for the intended use. The compression members 26, 26 are, of course, provided with suitable cross braces 44 to properly strengthen the boom assembly.

The cable or hoist drums 46 is mounted on the platform 48 carried by the compression members and is driven by the hydraulic motor 50 through a suitable gearing in housing 52. The hydraulic motor is provided with suitable hose connections 54, 56 which are connected to the hydraulic mechanism on the fork truck for control of the motor from the fork truck. The cable 58 is reeved over a pulley60 on the outboard end of the boom and then runs down through block 62 and terminates at the hook 64 which can be hung on a suitable eyelet 66. The block 62 is provided with a hook 68 and this a-rrangement is for a double line hoisting of a load on the hook. If for some reason a single line operation is desired, the block 62 can be removed and a hook 64 can be employed.

The plates on either side of the sheave 60 serves to support the hook 70 at the extreme outward end of the boom. This hook is designed to facilitate removal of the unit from the fork truck. For example, when the crane is not needed the hook 70 is lowered to engage a suitable hook or other device 72 on the wall of the building or the like 74 and tension member 28 is disconnected from the fork truck by removal of the pin 76. The fork truck now can be backed away from the crane which will be held by reason of the hook 70 engaging the hook on the Wall. Of course, the stirrups merely slide off the forks. The crane or boom can now be left stored against the building ready for future use. When the unit is to be placed into use the forks are aligned with the stirrups and the fork truck is advanced until the stirrups are against the back member 22. Then the tension member is connected whereupon the hook 70 can be disengaged from hook 72 and the crane is ready for operation. Of course, the hydraulic ram on the tension member and the hydraulic hoist motor will have to be connected through suitable hydraulic connections.

The provision of the hook on the free end of the crane makes this unit most versatile and easy to place into operation or to remove from the fork truck. Without such provision the general problem of handling the unit to mount it or dismount it becomes rather cumbersome.

A fork truck provided with a crane of this type is a very versatile piece of equipment in that the crane can be elevated by the usual elevating mechanism of the fork truck and the angle of the entire fork assembly including the crane can be changed as well as providing for changing the boom angle by adjusting the length of the tension member. The net effect is to provide a crane which in many respects is more versatile than specialized small crane units. The present arrangement can be provided at relatively low cost making it possible for persons having need for a crane only occasionally to have the benefit of a crane without a great investment.

Although but a single embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A detachable crane for fork trucks or the like, comprising, a boom including tension and compression members provided with means for attaching the boom to a fork truck, a sheave at the free end of the boom, a hoist drum mounted on one of said members, a cable reeved from the drum over the sheave, first hook means attached to said cable and second rigidly mounted hook means on the free end of the boom, vertically disposed means for engaging said second hook means whereby the crane can be restrainted while the fork truck is backed away to thereby facilitate removal of the crane from the fork truck.

2. A crane according to claim 1 in which the hoist drum includes a hydraulic motor for the drum.

3'. A crane according to claim 2 in which the tension member includes hydraulic means for altering the length of the tension member.

References Cited by the Examiner UNITED STATES PATENTS 2,760,661 8/1956 Wight et a1 214-620 2,820,561 1/1958 Meagher 214--620 3,207,347 9/1965 Ehrlich 214620 GERALD M. FORLENZA, Primary Examiner.

R. B. JOHNSON, Assistant Examiner. 

1. A DETACHABLE CRANE FOR FORK TRUCKS OR THE LIKE, COM PRISING, A BOOM INCLUDING TENSION AND COMPRESSION MEMBERS PROVIDED WITH MEANS FOR ATTACHING THE BOOM TO A FORK TRUCK, A SHEAVE AT THE FREE END OF THE BOOM, A HOIST DRUM MOUNTED ON ONE OF SAID MEMBERS, A CABLE REEVED FROM THE DRUM OVER THE SHEAVE, FIRST HOOK MEANS ATTACHED TO SAID CABLE AND SECOND RIGIDLY MOUNTED HOOK MEANS ON THE FREE END OF THE BOOM, VERTICALLY DISPOSED MEANS FOR ENGAGING SAID SECOND HOOK MEANS WHEREBY THE CRANE CAN BE RESTRAINTED WHILE THE FORK TRUCK IS BACKED AWAY TO 